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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Number of additional shares authorized for issuance under share-based payment arrangement.

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Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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Stock-Based Compensation - Narrative (Details)			3 Months Ended
Stock-Based Compensation - Narrative (Details)	May 28, 2020	May 25, 2016 shares	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 shares	Jul. 15, 2020 shares
Stock Based Compensation Details [Line Items]
Reverse stock split, conversion ratio	0.10
Number of options issued (in shares)			1,754,120
Unrecognized compensation costs \| $			$ 1,700,000
Plan 2016
Stock Based Compensation Details [Line Items]
Shares approved and authorized (in shares)		4,000,000
Maximum number of shares to any individual (in shares)		1,000,000
Shares of common stock options outstanding (in shares)			18,742		18,561,000
Shares available for grant (in shares)			1,329,630		4,430,447
Plan 2016 \| Common Stock
Stock Based Compensation Details [Line Items]
Shares of common stock options outstanding (in shares)			1,977,938		249,486,000
Amended 2016 Plan
Stock Based Compensation Details [Line Items]
Shares approved and authorized (in shares)						400,000
Additional shares authorized (in shares)		2,000,000
July 2020 Amendment
Stock Based Compensation Details [Line Items]
Shares approved and authorized (in shares)						4,400,000
Employee Stock Option
Stock Based Compensation Details [Line Items]
Compensation expense \| $			$ 100,000	$ 400,000
Shares of common stock options outstanding (in shares)			2,228,647		507,295
Number of options issued (in shares)			1,754,120
Restricted Stock
Stock Based Compensation Details [Line Items]
Compensation expense \| $			$ 17,700	$ 57,100
Shares of RSUs outstanding (in shares)			1,379,465
Unrecognized compensation costs \| $			$ 1,200,000
Restricted Stock \| Minimum
Stock Based Compensation Details [Line Items]
Vesting period			1 year
Restricted Stock \| Maximum
Stock Based Compensation Details [Line Items]
Vesting period			4 years
Restricted Stock \| Plan 2016
Stock Based Compensation Details [Line Items]
RSUs outstanding (in shares)					181,000